Invalidating Wudu' after offering Shaf` Prayer

Q 1: A man offered `Isha' (Night) Prayer and Shaf` (two units of Prayer, particularly before the final unit of the odd-number prayer). While he was offering Witr (Prayer with an odd number of units), he passed gas, should he repeat Wudu' to repeat both Shaf` and Witr or not?

A: A person should repeat only the final single Rak`ah of Witr if while offering it on its own he passes gas. However, he should repeat both Shaf` and Witr, if while offering them together with one Taslim (salutation of peace ending the Prayer), he passes gas before saying Taslim. It is worth mentioning that Shaf` and Witr are supererogatory, not obligatory acts of worship.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.